Impact wrench



Aug. 19, 1947. L. P. FosNo'r 2,425,793

IMPACT WRENCH Filed Feb. 10. 1943 2 Sheets-Sheet 2 @7 j g 5 445 y JNVENToR.

oz//s P Eos/vor A TTORNEY.

Patented Aug'. 19, 1947 IMPACT WRENCH l Louis Fosnot, Aurora, Ill., assignor to Independent Pneumatic lool Company, Chicago, Ill., a corporation of Delaware Application February 10.1943, serial No. 475,377

This invention relates to improvements i-n portable power operated impact wrenches and similar tools lfor screwing up and unscrewing nuts and bolts by power.

The invention, while relating to tools of the character referred Lto, is particularly concerned with the impact clutch mechanism employed in such tools for delivering a succession or series of rotational impacts or hammer blows on the clutch jaws to tighten the nut or bolt after it .has fbeen set or to loosen a tight nut or bolt on removing the same, the invention having among its principal objects the following:

To provide an impact clutch mechanism in which the rotary effort of the driving or tool motor is disengaged from the hammer member of the clutch at the moment of impact of the clutch elements carried by the hammer member on the clutch jaws whereby the tool motor may continue its rotation uninterruptedly under the power supplied thereto to aid in withdrawing the clutchyelements from the jaws upon the termination of an impact thereon and to reset the clutch .elements into the path of the jaws to repeat the impact or hammer blows on the jaws in the operation of the tool;

To provide an impact clutch mechanism in which the hammer member is revolvably mounted relatively to the driving and the anvil members of the clutch whereby the hammer member and its clutch elements are free to recoil upon delivering an impact or hammer blow on the jaws and by such recoil aid in withdrawing the clutch elements from the clutch jaws to declutch the clutch;

To provide an impact clutch mechanism in 18 Claims. (Cl. 192-305) 2 and easily moved into the. path of the jaws to clutch the same and to withdraw the clutch elements from the jaws in either direction of rotation of the driving or tool motor; and

To provide an impact clutch mechanism which strength, mass and ruggedness to impart the] necessary powerful impacts or hammer iblows on the clutch jaws as demanded for a practical impact tool.

which the speed of. and .the load on, the driving or tool motor remain practically constant during each of its revolutions making it possible to drive the impact'tool by any type of reversible tool motor, either pneumatically or electrically operated;

To provide an impact clutch mechanism in which the impact blows are delivered at the largest radius of the mechanism in order to dbtain the maximum power for the blows comparative to the size and weight of the tool;

To provide an impact clutch mechanism in which the withdrawing means for the clutch elements may comprise cooperating cam slots and lugs or pins on the respective driving and clutch elements for simplicity and compactness of the clutch construction;

To provide an impact clutch mechanism in which the cam slots are so constructed and arranged that the clutch elements may be readily The invention consists further in the featres hereinafter described and claimed.

In the accompanying drawings- Fig. 1 vis a longitudinal sectional view with parts in elevation of my improved impact tool;

Fig. 2 is a cross-sectional view taken on line 2 -2 of Fig. 1 'showing the impact or clutch elements in driving engagement with the anvil jaws;

Fig. 3 is a similar sectional view showing the impact or clutch elements approaching the anvil jaws preparatory to delivering a rotational hammer blow thereto;

Fig. 4 is a cross-sectional view taken on line 4-4 of Fig. 1 with parts broken away showing the cam means employed for withdrawing the impact or clutch elements from the anvil jaws upon termination of an impact thereon;

Fig. 5 is a disassembled view of the various parts of the clutch device, the parts being shown in perspective and positioned in the order of their assembly in the clutch unit and Fig. 6 shows a modification of the cam slot to 'be later described.

In the accompanying drawings, I have shown the impact clutch of my invention applied to a portable hand held, hand manipulated power tool of the pneumatically operated type, the outside motor case I oi which is provided with a side handle 2 containing a supply passage 3 for furnishing compressed air to the tool motor located within said motor case. The motor case i and the handle 2 may be in the form of a one-piece casting of the desired light metal or other material as employed for portable tool design.

The handle 2 is equipped with a throttle valve 4 spring biased to a normally closed position and opened by a. trigger block 5 slidably mounted within the handle for controlling the supply of motive fluid to the tool motor. The trigger block 5 is disposed in the handle 2 in position to be readily and easily depressed by the iinger of the operators hand grasping the handle for opening the valve 4 as will be apparent from Fig. 1. The

handlef2 is provided at the outer end of its passage 3 with a nipple 6 for connecting the tool to an air supply hose (not shown). There is also a metering valve 1 and an oil feed regulator 8 for the passage 3 mounted within the handle 2 in advance of the throttle valve 4. These parts are not concerned with my present invention and need not be further described.

The too1 motor shown in Fig. 1 is of the rotary type having a rotor 9 vequipped with radial blades I slidably mounted in slots II in therotor and working in conjunction with a cylinder I3 doweled or otherwise xed against rotation in the motor case as shown. The cylinder I3 iselamped in the motor case between its end plates I4, I4, which mount the ball bearing units I5, I5 for the shaft sections I6, I6 at the opposite ends of the rotor. A governor device I1 in the top section I8 of the motor case is driven by the rotor 9 and functions through a lever I9 and a valve unit 20 to automatically control the =volume of live air supplied to the tool motor in keeping with the load thereon as well understood in this art.

The rotor 9, as in motors of the kind shown, is eccentrically disposed within the cylinder I3 and has contact therewith at one point in its circumference to divide the cylinder into two crescent shaped chambers for the expansion and exhaust, respectively, of the live air supplied to the motor for rotating it. The motor has the necessary complement of ports and passages for the air as well understood, the exhaust ports in the cylinder for its low pressure side being indicated at 2| in Fig. 1.

A reversing valve 22 is revolvably mounted in the motor case I between the rotor 9 and the valve 4 as shown herein. This valve serves to change the flow of live air to the motor chambers to control the direction of rotation of the rotor. The rotor is rotated in a, right-hand or clock-wise direction to screw up a nut or bolt having a righthand thread, while the rotor is rotated in a lefthand or counterclock-wise direction to screw up a nut or bolt having a left-hand thread or to unscrew one having a right-hand thread. The valve 22 is turned by a handle member 23 on the outside of the motor case I as shown in Fig. 1. A check device (not shown) may be incorporated in the tool structure to hold the valve 22 in its adjusted positions. The passages and ports in the tool to take care of the ow of live air to the motor cylinder I3 from the passage 3 through the valve 22 need not be shown or described, all being well understood in this art.

The impact clutch mechanism of my invention is located at the forward end of the tool within a housing section 24 in the form of a casing bolted or otherwise xedly secured tothe motor case I as will be apparent from Fig. 1. The for- Ward or outer end of the case 24 is provided with a bushing 25 which provides a bearing for the spindle portion 26 on the driven or anvil member 21 of the clutch device. The spindle 26 is fashioned to receive and drive a nut or bolt head engaging socket 28 as shown in Fig. 1. The socket 28 is applied as an attachment to the spindle 26, diierent sockets being provided for different sizes and shapes of nuts and bolts within the range for which the particular too1 is provided. A conventional check connection (not shown) may b-e employed to hold a socket 28 from dropping out of the spindle when the tool is raised or carried about. A bolt to be set by the tool is shown at 29 in Fig. 1`.

align with the axis of the rotor 9.

The anvil member 21, as shown in perspective in Fig. 5, is in the form of a cylindrical cup open at its upper end and closed at its lower end by an end wall 38 from which depends the spindle 26. The cylindrical body portion of the anvil member 21 is hollow and is provided with relatively large diametrically disposed openings 3 I, 3| with jaw members 32, 32 therebetween. These jaw members 32 extend axially of the anvil member and the latter has an outside diameter to locate the jaws 32 relatively close to the inner side of the casing section 24 when the parts are assembled as shown in Figs. 2 to 4. The opposite side edges or surfaces 33, 34 of the jaws' 32 receive the impact blows of the impact or clutch elements to be presently described. With the jaws so constructed, it will be apparent that the clutch device may function in either direction o f rotation of the tool motor.

Concentrically disposed within the anvil member 21 is alcarrier 35 comprising upper and lower driver plates'36, 31 and an interposed shaft 38 connecting the plates for rotating them in unison.

The upper plate 36 is located at the upper end of the anvil member 21, while the lower plate 31 is located at the lower end of the anvil member adjacent its bottom wall 38. The upper plate 36, in the embodiment shown, is integrally formed with the shaft 38, while the lower plate 31 is separately formed in respect to the shaft for assembling the parts as will be apparent from Fig. 5. The driving connection between the lower plate 31 and the shaft 38 comprises a hexagonal section 39 milled on the shaft to fit within a similarly formed center opening 48 in the lower plate. The lower portion 4I of the shaft 38 extends below the lower. plate 31 into the anvil spindle `26, the latter being made hollow for this purpose and valso to mount a roller bearing unit 42 for the anvil spindle as shown. A thrust plate 43 is interposed between the lower plate 31 and the anvil wall 30 as shown. The plates 36, 31 have a diameter slightly less than the inside diameter of the anvil member 21 and the parts The upper plate 36 has an arbored socket 44 to receive the like shaped end of the shaft section I6 of the rotor 9 for rotating the carrier 35 in unison with the rotor by the direct drive connection between them.

A revolvable hammer member 45 in solid cylindrical form, except for its diametric cross-slot 46, is rotatably mounted Within the carrier 35 about th'e shaft 38 between the plates 36, 31. The hammer member conforms substantially to the inside diameter of the anvil member 21 between the jaws 32, 32 and has suflicient mass or weight to deliver strong and powerful rotational hammer blows against the jaws through impact clutch elements or dogs 41, 41 slidably mounted in the hammer slot 46. This slot extends completely through the hammer 45 and a pair of these impact or clutch elements 41 are mounted therein, one at each end of the slot. The slot 46 and the dogs 41 are rectangular in shape, the dogs being in solid block form substantially filling the portions of the hammer slot occupied by the dogs and having sliding contact with the flat walls of said slot. This arrangement holds the dogs 41 against rotation relatively to the hammer member 45 and it also guides the dogs with' a rectilinear movement into and out of the orbital path of the anvil jaws 32 through the anvil openings 3l. The path referred to is about the outer circumference ofl the hammer member 45 as shown herein.

Pins or rods 48, 48. one for each impact dog 41, have a pressed fit in a longitudinal bore 49 in the associated dog for retaining thesame in the hammer slot 46. To do this, the pins 48 extend beyond the opposite ends of the dogs 41 and engage in radial slots 50, U in the solid body portion Y of the hammer member 45 overlying the top and bottom portions of the slot 46. The slots 50 are elongated so that the dogs 41 may slide back andv forth in the hammer s1ot'46 to clutch and declutch the anvil jaws 32 in the operation of the clutch'. l f

The impact dogs v41 are moved outwardly by centrifugal force and inwardly by a cam action to be next described. Each dog 41 has a rib formation 5l at its outer end to give maximum time for the dogs to move outwardly and engage the jaws i2 and also to deliver less oblique blows thereon. The inner ends of the dogs 41 are recessed longitudinally` as at 52 so that the dogs may embrace and properly' engage the shaft 38 at the limit of their inward movement to relieve the pins or rods 48 of this stop action.

The cam action comprises a pair of cam slots 53, 53 in each of the driver plates 36, 3l. 'Ih'e cam slots 53 are similarly arranged in each plate 35, 3l on opposite sides of the carrier axis and disposed to receive the adjacent end portions oi the pins or rods 48. In this respect, the pins form lugs on the ends of the impact dogs to extend into the cam slots. 'I'he latter are substantially arcuate in. shape and have widths suicient to act on the lugs 48 to withdraw the dogs 41 from the anvil jaws di in the operation of the clutch as will presently appear. l'llhe hammer member 45 has aligned center openings 54, 54 intersecting the slot tit at its upper and lower ends to mount th hammer member 45 on the shaft 38.

The mechanism shown and described operates as follows:

Supplying live air to the tool motor through` the throttle valve 4 rotates the motor in the direction for which' the valve 22 is set. In the drawings, Ihave shown the4 valve 22 set for a right hand or clock-wise rotationas indicated by the arrows a in Fig. 3. The rotor 9 drives the carrier 35 and through the lugs 48 in the cam slots 53 imparts rotation to the hammer member 45. The rotor attains speed quickly and centrifugal force moves the dogs 41 outwardly into the orbital path of the jaws 32 through the openings 31 in the anvil member 21. The maximum extent of this outward movement occurs when the lugs 48 reach the mid or outermost portions b of the cam slots 53 as shown in Fig. 3. When the dogs 41 engage the jaws 32 a clutched connection is established between the rotating carrier 35 and the anvil member 21 to screw up or Fig. 2.y The carrier 85 continues to revolve being 35 picks up the hammer member 45 and rotates' the same in the direction of rotation of the motor. Centrifugal force now acts on the dogs 41 causing a, relatively angular displacement between the dogs and the cam plates to bring the dogs again into striking positions and speed the hammermember in unison with the rotating carrier 35. This takes place approximately when the center of the dogs are in a position at or approaching 90 degrees from the position shown in Fig. 2 or in the full line position shown in Fig.y 3. The outer ends of the dogs are now in the orbital path ofthe jaws 32 and the parts continuing to be driven strike with strong rotational hammer .blows against the jaws to further tighten the nut or bolt.' This action repeats as long as the tool is held in engagement .with the nut or bolt and a comparatively tight clamping results.

It will be noted that the hammer member 45 is comparatively heavy, also the dogs are heavy and that the anvil jawsv are at a considerable distance, outwardly from the center axis of the clutch device. The blows delivered are therefore powerful comparative to the size and weight of the tool and its impact clutch mechanism. It will also be noted that the momentum of the motor rotor apply the nut or bolt engaged by the socket 28.

This clutched connection is retained until the nut or bolt is screwed down or set against the work, whereupon the clutch releases causing the dogs 41 to impart a succession or series of rotational hammer blows on the jaws 32 in the continued rotation of the motor to further tighten the nut or bolt. In this operation, the dogs 41 strike against the side edges 33 of the jaws as A shown in Fig. 2.

Upon striking the sides of the anvil jaws 32', when the anvil member 21 is thus held solidly against rotation by the tightened nut or bolt, the hammer member stops rotating at the instant of the impact and recoils backwardly from the struck surfacev 33 being thrown back to approximately the position indicated by the line c in is not utilized in'delivering the blows andthat there is no solid connection between the driver: or carrier and the hammer member 45.* It is also pointed out that there is no stopping of the tool' motor at each blow delivering impact on the ani vil jaws and hence any type of reversible tool motor, either electrically or pneumatically driven, may be employed with my improved impact clutch device. With a constantly rotating tool motor, a'quick and rapid action 0f the clutch device is possible. It is to be understood that when removing or unscrewing a nut or bolt with a right hand thread or applying one with a left hand thread that the dogs 41 strike against the side surfaces 34 of the clutch jaws 32.

To relieve undue rubbing or wear of the lugs 48 on the edges of the cam slots 53, the shaft 38 provides the inner stop for the dogs 41, while the outer ends of the slots 50 may provide the outer stops.

In Fig. 6, I have shown a cam slot 53a of a slightly different contour than the slot 53 in the preceding figures. Fundamentally, both cam slots perform the same function to withdraw the dogs from the anvil jaws following the delivery of an impact thereon. The cam slot shape in Fig. 6, however, has a longer dwell b at its midportion and more radially disposed camming portions d at the ends of the slots to allow for a. freer recoil of the hammer member than the slot 53 in respect to which the recoil is likely to be dampened by the force absorbed in moving the dogs inwardly. Moreover, with the camming portions d closer to the radial than in the slot v53 centrifugal force moves the dogs outwardly to theirl clutching and striking positions earlier as 35 and a higher rotative speed for more intense hammer blows on the jaw results. In both slots, as herein shown, one camming portion operates to withdraw the dogs in one direction of rotation of the tool motor, while the other camming portion withdraws the dogs in the reverse direction of rotation.

The details of construction and arrangement of parts shown and described may be variously changed and modied without'departing from the spirit and scope of my invention, except as f pointed out in the annexed claims.

I claim as my invention: 1. An impact clutch comprising relatively rotatable driving, hammer and anvil members, said anvil member having spaced jaws, impact elements movably carried by the hammer and movable into the orbital path of the jaws to deliver i a series of rotational hammer blows thereto in the rotation of the hammer with the driving member relatively to the anvil, cam slots and cooperating lugs therefor coupling the driving member to the impact elements, said cam slots being substantially arcuate in shape and arranged with their outermost mid-portions disposed for the projection of the impact elements into the path of the jaws and their camming portions on opposite sides of said mid-portions to withdraw the impact elements from the jaws upon the termination of an impact thereon in either direction of rotation or the driving member, and means for reversely rotating the driving member.

2. An impact clutch comprising relatively rotatable carrier and anvil members, said anvil member having spaced jaws, said carrier having axially spaced plates and a shaft therebetween, a hammer revolvably mounted on the shaft between'said plates, impact elements slidably carried by the hammer and movable into the orbital path of the jaws to deliver a series of rotational hammer blows thereto in the rotation of the hammer with the carrier relatively to the anvil, said plates having cam slots therein on c-pposite sides of said shaft, lugs on the impact elements extending into saidslots, said cam slots acting on the lugs to impart rotation to the hammer from the carrier and to withdraw the impact elements from the jaws upon the termination of an impact thereon, and means for rotating the carrier.

3. An impact clutch comprising relatively rtatable carrier and anvil members, said anvil member having spaced jaws, said carrier having axially spaced plates and a, shaft therebetween, a hammer revolvably mounted on the shaft between said plates, impact elements slidably carried by the hammer and movable by centrifugal force into the orbital path of the jaws to deliver a series of rotational hammer blows thereto in the rotation of the hammer with the carrier relatively to the anvil, said plates having cam slots therein on opposite sides of said shaft, lugs on the impact elements extending into said slots, said cam slots acting on the lugs to impart rotation to the hammer from the carrier and for withdrawing the impact elements from the jaws upon the termination of an impact thereon, and vmea-ns for rotating the carrier, one of said plates and the lugs having releasable connection with the shaft and the impact elements, respectively, for assembling the hammer on the shaft and the impact elements inthe hammer.

4. An impact clutch comprising relatively rotatable carrier and anvil members, said anvil i 8 having axially spaced plates and a shaft therebetween, a hammer revolvably mounted on said shaft between said plates, impact elements slidably carried by the hammer and movable by centrifugal force into the orbital path of the jaws to deliver a series of rotational hammer blows thereto in the rotation of the hammer with the carrier relatively to the anvil, said plates having cam slots therein on Opposite sides of said shaft, lugs on the impact elements extending into said slots, said cam slots acting on the lugs to impart rotation to the hammer from the carrier and to withdraw the impact elements from the jaws following the termination of an impact thereon, and mean-s for rotating the carrier, said lugs being in the form of rods fitting in the impact elements and projecting beyond the same to extend into the cam slots.

5. An impact clutch comprising relatively rotatable driving, hammer and anvil members, said anvil member having spaced jaws, said hammer having a diametric cross-slot therein, a pair of impact elements slidably mounted in said hammer slot, one at each end thereof, for movement radially of the hammer into and out of said slot, said impact elements being movable by centrifugal force out of the hammer slot into the orbital path of the jaws to deliver a series of rotational hammer blows thereto in the rotation of the hammer with the driving member relatively to the anvil, means rotatable with the driving member and acting on the impact elements exteriorly of said slot for imparting rotation to the hammer from the driving member and for positively moving the impact elements back into the hammer slot from the jaws upon the termination of an impact thereon, and means for rotating the driving member.

6. An impact clutch comprising relatively rotatable driving, hammer and anvil members, said anvil member having spaced jaws, said hammer having a diametric cross-slot therein, a pair of impact elements slidably mountedin said hammer slot, one at each end thereof, and movable by centrifugal force into the orbital path of the jaws to deliver a series of rotational hammer blows thereto in the rotation of the hammer with the driving member relatively to the anvil, coacting cam slots and lugs carried by the driving and the impact elements, respectively, for imparting rotation to the hammer from the driving member and for withdrawing the impact elements back into the hammer slot from the jaws upon the termination of an impact thereon, and means for rotating the driving member, said hammer having radial slots to guide the lugs and limit the outward movement of the impact elements.

7. An impact clutch comprising relatively rotatable carrier and anvil members, said anvil member having spaced jaws, said carrier having axially spaced plates and a shaft therebetween, a hammer revolvably mounted on the shaft between said plates, said hammer having a diametric cross-slot therein, a pair of impact ele ments slidably mounted in the hammer slot, one at each end thereof, and movable by centrifugal force outwardly from said slot into the orbital path of the jaws to deliver a series of rotational hammer blows thereto in the rotation of the hammer with the carrier relatively to the anvil, said plates having cam slots therein on opposite sides of said shaft, lugs on the impact elements extending into said cam slots, said cam slots acting on the lugs to withdraw the impact elements elements and serving as a stop back into the hammer slot from the jaws in the rotation of the lcarrier relatively to the anvil, and means for rotating the carrier, said shaft extending between the inner ends of the impact to limit their inward movement. Y

8. An impact clutch comprising relatively rotatable carrier and anvil members, said anvil member having spaced jaws, said carrier having axially spaced plates and a shaft therebetween, a hammer revolvably mounted on the shaft between said plates, said hammer having a diametric cross-slot and concentrically disposed bores therein intersecting said cross-slot to receive said shaft, impact elements slidably mounted in said hammer slot and movable by centrifgual force into the orbital path of the jaws to deliver a series of rotational hammer blows thereto in the rotation of the hammer with the carrier relatively to the anvil, said plates having cam slots therein on opposite sides of said shaft, lugs on the impact elements extending into said cam slots, said cam slots acting on the lugs to impart rotation to the hammer from the carrier and to withdraw the impact elements from the jaws upon the termination of an impact thereon, and means for rotating the driving member, said shaft providing a stop to limit the inward movement of the impact elements and said hammer having radial slots to guide the lugs and to limit the outward movement of the impact elements.

9. An impact clutch comprising relatively rotatable driving, anvil and hammer members and interposed clutch members radially and rectilinearly slidable on the hammer,` said hammer being constantly maintained by the driving member in concentric relation with the anvil, said clutch members serving to deliver a series of rotational hammer blows on the anvil in the rota-l -tion of the hammer member with the driving member relatively to the anvil, means responsive to the relative rotation of the driving and hammer member in reverse directions following impact of the clutch members with the anvil for positively declutching the same by a force applied on the clutch members exteriorly of the hammer and transversely to the axis of rotation thereof, and means for rotatingthe driving member.

10. An impact clutch comprising relatively rotatable driving, anvil and l hammer members and interposed clutch members radially and rectilinearly slidable on the hammer, said hammer being constantly maintained by the driving member in concentric relation with the anvil, said clutch members serving to deliver a series of rotational hammer -blows on the anvil in the rotation of the hammer member with the driving member relatively to the anvil, means responsive to the rotation of the driving member and the recoil of the hammer member following impact of the clutch members with the anvil for positively declutching the same by a force applied on the clutch members exteriorly of the hammer and l transversely of the rotation thereto, and means for rotating the driving member.

11. In a portable impact tool of the character described comprising in combination,4 a power actuated tool motor, an impact clutch having Arelatively rotatable driving, anvil and hammer members and interposed clutch elements, the lat ter being radially and rectilinearly slidable on the hammer, said hammer being constantly maintained by the driving member in concentric relation with the anvil, said clutch elements serving to deliver a series of rotational hammer blows t0 the anvil member in the rotation o! the hammer the anvil upon the termination of an impact thereon by a force applied on the clutch members exteriorly of the hammer and transversely to the axis of rotation thereof. y

12. In an impact tool of the character described comprising in combination, a power actuated tool motor, an impact clutch having relatively rotatable driving, anvil and hammer members and interposed clutch elements, the latter being radially and rectilinearly slidable on the hammer, said hammer being constantly maintained by the driving member in concentric relation with the anvil, said clutch elements serving to deliver a series of rotational hammer blows to the anvil in the rotation of the hammer with the driving member relatively of the anvil, said driving member having direct connection with the `tool motor for rotation thereby, and means driven by the driving member for positively declutching the 'clutch elements from the anvil upon the termination'of an impact thereon by a force applied on the clutch members transversely of the axis of rotation of the hammer in the continued rotation of the driving member by the tool motor ahead of the hammer member.

said clutch members serving to deliver a series of rotational hammer blows to the anvil in the rotation of -the hammer member with the driving member relatively to the anvil, said driving member having direct connection with the tool motor for rotation thereby, and means driven by the driving member for positively declutching the clutch members from the anvil upon the termination of an impact thereon by a force applied on the clutch members exteriorly of the hammer and transversely'of the axis of rotation thereof, said means being constructed and arranged to act in either direction of rotation of the driving member by the tool motor.

14. An impact clutch comprising relatively rotatable driving, hammer and anvil members,

said anvil member having spaced jaws arrangedl ing member in concentric relation with said jaws,

impact elements slidably carried by and having rectilinear movement radially .of the hammer into and out of the path of the jaws for delivering a series of rotational hammer blows thereto in the rotation of the hammer with the driving member relatively to the anvil, means interconnecting the impact elements with the driving member for imparting rotation to the hammer from the driving member through said impact elements and acting thereon transversely to the hammer axis for positively sliding the impact elements out of the path of the jaws upon' termination of an impact thereon, and means for rotating the driving member.

15. An impact clutch comprising relatively rotatable driving, hammer and anvil members, said anvil member having spaced jaws arranged in an orbital path about the hammer and said hammer being constantly maintained by the driving member in concentric relation with said jaws, impact elements slidably carried by and having rectilinear movement radially of the hammer into and out of the orbital path of said jaws for delivering a series of rotational hammer blows thereto in the rotation of the hammer with the driving member relatively to the anvil, cam means adjacent to the opposite ends of the impact elements for interconnecting the Same with the driving member, said cam means serving to impart rotation to the hammer from the driving member through said impact elements -and acting thereon transversely to the hammer axis for positively sliding the impact elements out of the path of the jaws upon termination of an impact thereon, and means for rotating the driving member.

16. An impact clutch comprising relatively rotatable driving, hammer and anvil members, said anvil member having spaced jaws arranged in an orbital path about the hammer and said hammer being constantly maintained by the driving member in concentric relation with said jaws, impact elements slidably carried by and having rectilinear movement radially of the hammer member, said impact elements being slid by centrifugal force into the path of the jaws for delivering a series of rotational hammer blows thereto in the rotation of the hammer with the driving member relatively to the anvil, means having cam slots carried by and rotatable with the driving member exterior of the hammer, lugs on the impact elements extending into said slots, said cam slots serving to impart rotation to the hammer through said lugs and acting thereon transversely to the hammer axis for positively sliding the impact elements out of the path of the jaws upon termination of an impact thereon, and means for rotating the driving member.

17. An impact clutch comprising relatively rotatable driving, hammer and anvil members,

- said anvil member having spaced jaws arranged 12 i rectilinear movement radially of the hammer into and out of the path of the jaws for delivering a series of rotational hammer blows thereon in the rotation of the hammer with the driving member relatively to the anvil, means having cam slots carried by and rotatable with the driving member, lugs on the impact elements extending into said cam slots, said cam slots having their outermost portions arranged for the projection of the impact elements outwardly of the hammer into the path of the jaws and theiry camming portions extending inwardly to positively slide the impact elements from thejaws upon the termination of an impact thereon, and means for rotating the driving member.

18. A reversely acting impact clutch comprising relatively rotatable driving, hammer and anvil members, said anvil member having spaced jaws arranged in an orbital path about the hammer and having impact receiving surfaces on the opposite sides of the jaws, said hammer being constantly maintained by the driving member in concentric relation with said jaws, impact elements slidably carried by the hammer and having rectilinear movement radially of the hammer into and out of the path of the jaws, said impact elements having striking surfaces on opposite sides for deliveringa series of rotational hammer blows to the jaws in either direction of rotation of the hammer with the driving member relatively to the anvil, means interconnecting the impact elements with the driving member for imparting rotation to the hammer from the driving member through said impact elements and acting thereon transversely to the hammer axis in reverse directions vof rotation of the driving member for positively sliding the impact elements out of the path of the jaws upon the termination of an impact thereon, and means for reversely rotating the driving member.

LOUIS P. FOSNOT.

REFERENCES CITED The following references are of record in the `iile of this patent:

UNITED STATES PATENTS Amtsberg June 9, 1942 

